Watch arbor and pivot



(No Model.)

G. S. HEATH 8; A. P. GHAMPLIN. WATCH ARBOR AND PIVOT.

361I9'46- Patented Apr. 1887? L 4.14am elm/ UNITED STATES PATENT OFFICE.

GEORGE S. HEATH AND AMOS F. CHAMPLIN, OF HARTFORD, CONNECTICUT.

WATCH ARBOR AND PIVOT;

SPECIFICATION forming part of Letters Patent No. 361,946, dated April 26, 1887.

Application filed September 9, 1885. Renewed August 5, 1886. Serial No. 210,129. (No model.)

of our device separated from each other. Fig.

2 is a like view of the same combined for use; and Figs. 3 and {i are central longitudinal sections of the same, and show, respectively, the

- pivots made from one piece and from separate pieces. 7

Letters of like name and kind refer to like parts in each of the figures.

In the manufacture-of watch-movements it has heretofore been customary to construct each arbor with its pivots from one and the same piece of metal; but when so constructed it has been'difificult, if not impossible, to produce perfectly round straight pivots with square shoulders, and to insure the same plane of rotation for the arbor and pivots.

To remedy these defects and to lessen the cost of manufacture is the object of our invention, to which end said invention consists in an arbor or arbor and pinion constructed from one piece and provided with a straight axial opening, in combination with pivots which are formed from a straight metal rod having substantially the diameter of said opening and are inserted into and held frictiontight within the same, substantially as and for the purpose hereinafter specified.

In the carrying of our invention into practice an arbor, A, and, if desired, a pinion, a, are constructed from a piece of metal, preferably one of the compositions known under the general designation of brass, and provided with a straight round axial opening, a. Said arbor has such length as to cause it to fill the space between the movement-plates with such closeness as may be desired, having in view the necessary amount of end-shake.

The axial opening a has the diameter of the proposed pivots, and into the same is inserted a metal rod, a preferably steel,which closely fills said opening and is secured therein by friction, soldering, or by any well known means. The ends of said rod project to any desired distance from the ends of the arbor A, and constitute pivots for the same, the article thus constructed having the same general shape as those constructed in the usual manner.- Instead of being formed from one piece of metal, said pivots may be made from two pieces, if desired.

By this method of construction many important advantages are secured. The pivots may be made from drawn or rolled wire and placed in position without removing the dense hard surface produced by such operation, by which means they will have much greater strength and durability than could be obtained from the use of steel of equal sizegvhich had been reduced to shape by turning, and consequently can be made materiallysmaller than would otherwise be practicable.

Pivots thus made and inserted have equal strength throughout their length, and when in place can be bent without breaking, while as heretofore constructed the weakest point of a pivot was the point where it was united to the arbor, and a comparatively light strain would cause a breakage at such point. Our 0011- struction of the arbor and pivots renders practicable the successful hardening of the latter, as they can be easily and safely straightened if warped during the operation of hardening, while if they constituted parts of the arbor such operation would be very difficult and liable to cause breakage.

A further and important advantage arises from the practicability of using composition or brass for pinions, as when made from such material the leaves are more easily and quickly out; they can be out much smoother than would 4 be possible if steel were used; said leaves require neither hardening nor polishing, and such pinions will mesh into and run with composition wheels without appreciable wear and with a minimum of friction. Again, in the cutting of composition pinions, there is but a fraction of the amount of wear to the cutters that occurs in the cutting of steel pinions, so that thelife of such cutters is largelyincreased, the expense is lessened, and there is lessvariation in the shape and sizeof the leaves of the pinions. Again, by our method of construction absolute uniformity is practicable in the lengths of any number of arbors, and perfectly-square shoulders are produced at each end, by which means the required endshake of an arbor can be determined beforeits insertion within a movement, the necessity which has heretofore existed for fitting each arbor to place is avoided, and the arbors of a line of movements can be made interchangeable. Finally, by the use of separate pivots the breakage of one oi'sueh parts involves but slight expense for repairs, as the'broken pivot can be easily and readily replaced by a new pivot which will be axially true without turning.

WVe are aware that gas-pipe provided within each end with a gndgeon which had its inner end reduced in size to enable it to enter into and be pinned therein has been used for a shaft, and do not claim such construction.

GEORGE S. HEATH. AMOS-F. OHAMPLIN.

\Vitnesses:

T. It. LiUoi-i'r'oN, War/rm: 1?. Cinmrnnntm. 

